Heat exchanger with expansible tube seal



July 25, 1967 w. c. MARTIN, JR. 3,332,479

3 HEAT EXCHANGER WITH EXPANSIBLE TUBE SEAL Filed Jan. 2, 1964 2 Sheets-Sheet 1 FIG. I

INVENTOR.

WILLIAM C. MARTIN, JR.

ATTORNEY.

July 25, 1967 w. c. MARTIN. JR

,HEAT EXCHANGER WITH EXPANSIBLE TUBE SEAL 2 Sheets-Sheet 2 Filed Jan. 2, 1964 HH ll llllillH INVENTOR. WILLIAM C. MARTIN, JR.

ATTORNEY.

United States Patent C 3,332,479 HEAT EXCHANGER WITH EXPANSIBLE TUBE SEAL William C. Martin, .liu, Syracuse, N.Y., assignor to Carrier Corporation, Syracuse, N.Y., a corporation of Delaware Filed Jan. 2, 1964, Ser. No. 335,246 11 Claims. (Cl. 165158) This invention relates to heat exchange apparatus, and more particularly to a heat exchanger for use in refrigeration systems.

Heat exchangers may be thought of as devices for bringing primary heat exchange medium into heat exchange relationship with secondary heat exchange medium. A typical heat exchanger includes a plurality of longitudinally disposed heat exchanger tubes in a housing. In a heat exchanger of this type the area surrounding the exterior surfaces of the plural heat exchanger tubes may be in communication with the primary heat exchange medium while the area bounded by the interior surfaces of the heat exchanger tubes communicates with the secondary heat exchange medium. By this construction the plural heat exchanger tubes serve as the intermediary for bringing primary heat exchange medium into heat exchange rela-tionship with the secondary heat exchange medium.

The eflicacy of the heat exchanger requires that the primary and secondary heat exchange mediums be isolated one from the other. Since the plural heat exchanger tubes constitute the sole bridge between primary and secondary heat exchange mediums the seal between primary and secondary heat exchange mediums at each of the plural heat exchanger tubes is of critical importance.

Where heat exchangers of the type described are disposed in positions other than vertical, the heat exchanger tubes tend to sag. Tube sag may place an excessive strain on the seal between primary and secondary heat exchange mediums at the heat exchanger tubes with possible impairment or rupture thereof. Additionally, the amount of sag of each of the heat exchanger tubes may vary, destroying the design spacing between the tubes and bringing tubes into contact with one another. The flow of first and second heat exchange mediums through the heat exchanger may induce the heat exchanger tubes to vibrate causing contacting or closely adjacent tubes to strike one another.

To obviate sag of heat exchanger tubes, additional supports, commonly known as tube support sheets, may be placed at selected intervals in the heat exchanger housing. Each of the tube support sheets has a plurality of spaced tube receiving openings therein through which heat exchanger tubes pass. The surrounding tube support sheet structure is relied upon to limit movement of the tube in a radial direction and maintain selected spacing between tubes.

In constructions where tube support sheets are utilized the most effective support structure for maintaining the heat exchanger tubes in predetermined spaced relation relative to the housing and to each other is a support sheet having tube receiving openings dimensioned approximately equal to or slightly less than the outer dimension of the heat exchanger tubes. By this construction each heat exchanger tube is rigidly positioned against movement in a radial direction at the tube support sheet. However, assembly of the heat exchanger by moving the plural heat exchanger tubes axially through openings in the support sheet or sheets, becomes impossible or extremely difiicult. To allow movement of the heat exchanger tubes through the tube sheet openings during assembly of the heat exchanger, tube support is compromised by making the tube support sheet openings ice larger than the outer dimension of the heat exchanger tubes. This compromise arrangement provides a degree of support for the heat exchanger tubes, and at the same time permits movement of the heat exchanger tubes through the support sheets during assembly, and disassembly, of the heat exchanger. It does not, however, support the heat exchanger tubes tightly enough to eliminate sag of tubes between supports, and tube vibration.

To more effectively support the heat exchanger tubes, the heat exchanger tubes may be expanded into contact with the tube support sheets. This construction permits the use of support sheet openings with a dimension greater than the outer dimension of the heat exchanger tubes whereby movement of the heat exchanger tubes relative to the support sheet is expedited and at the same time results in a high degree of tube support through the subsequent expansion of each tube into tight engagement with the support sheet. However, this construction is expensive, time-consuming and often impractical. Where heat exchangers have a substantial axial length with a great number of relatively small diameter heat exchanger tubes and plural spaced support sheets, the magnitude of the problem facing the assembler in accurately locating and expanding that portion only of each heat exchanger tube opposite each of the tube support sheets through which the tube passes may be readily appreciated.

Conventional tube support sheets are normally formed from metal, usually steel. Contact between the steel support sheet and the outer surface of the heat exchanger tubes, which are normally copper, may result in galvanic erosion. This may be enhanced by the particular heat exchange fluid utilized in the system and by any tube vibration. Where the tube support sheet is formed from the same metallic material as the heat exchanger tubes, erosion induced by vibration of the heat exchanger tubes may occur. To obviate tube erosion, each heat exchanger tube should preferably tightly engage the support sheet surface defining the tube receiving opening. However, as noted heretofore, the known technique of expanding each tube into tight engagement with each of the tube sheets through which the tube passes is often impractical and always expensive.

It is a principal object of the present invention to provide a new and improved apparatus for use with heat exchangers operable to support heat exchanger tubes in predetermined spaced relationship relative to one another and to the heat exchanger.

It is an additional object of this invention to provide a unique apparatus for supporting heat exchanger tubes adapted to permit ready movement of the heat exchanger tubes relative thereto to facilitate assembly of the heat exchanger and operable, when exposed to heat exchange medium, to tightly grip each heat exchanger tube to prevent movement and vibration thereof.

It is a further object of the present invention to provide apparatus adapted to tightly grip heat exchanger tubes when the heat exchanger is joined to a refrigeration system and adapted to release the heat exchanger tubes upon separation of the heat exchanger from the system.

It is an object of the present invention to provide a new and improved method of making tube support sheets for heat exchanger apparatus.

It is a further object of the present invention to provide a new and improved tube support sheet structure.

This invention relates to heat exchanger apparatus adapted to communicate with a first heat exchange medium having at least one heat exchange member therein adapted to communicate with a second heat exchange medium, the combination comprising means for supporting the heat exchange member in the heat exchanger, the support means being spaced from the heat exchange memher and expansible means for operably securing the heat exchange member to the support means, the expansible means comprising a material which expands upon exposure to the first heat exchange medium.

The invention further relates to heat exchange apparatus comprising a housing defining a compartment adapted to communicate with a first heat exchange medium, a plurality of spaced heat exchanger tubes in the compartment adapted to communicate with a second heat exchange medium, and means for maintaining the heat exchanger tubes in predetermined spaced relationship to each other and to the housing including support means in the housing having tube receiving openings therethrough in predetermined spaced relationship one to another, each of the openings having a dimension greater than the outer dimension of the heat exchanger tubes and means for securing the heat exchanger tubes to the support means in response to the presence of the first heat exchange medium in the compartment.

The invention additionally relates to the method of making a tube support sheet for use in a heat exchanger having a plurality of heat exchanger tubes therein in which the steps consist in inserting a ring-like element in each of a plurality of spaced, generally cylindrical, recesses in one surface of a support sheet part having tube receiving openings therethrough coaxial with each of the recesses, placing a second tube support sheet part having a like number of similarly spaced, generally cylindrical, recesses with tube receiving openings therethrough coaxial with each of the recesses over the ring-like elements on the support sheet part, and fastening the support sheet parts together.

Other objects will be apparent from the ensuing description and drawings in which:

FIGURE 1 illustrates schematically a refrigeration system incorporating the present invention;

FIGURE 2 is a cross sectional view taken along line 11-11 of FIGURE 1 showing the tube support sheet;

FIGURE 3 is an enlarged fragmentary cross sectional view through the tube support sheet shown in FIGURE 2 illustrating the expansible tube gripping elements in expanded condition;

FIGURE 4 is an exploded view of apparatus for forming a tube support sheet of the type shown in FIGURE 3 of the drawings;

FIGURE 5 is a view showing an alternate tube support sheet construction; and

FIGURE 6 is a view of an apparatus for forming a tube support sheet of the type shown in FIGURE 5 of the drawings.

Referring particularly to FIGURE 1 of the drawings, there is shown a refrigeration system embodying the heat exchanger tube support structure of the present invention. The refrigeration system includes a compressor 12 having a suitable drive motor 14. Compressor 12 may be of any suitable type, for example, centrifugal, rotary or reciprocating; if desired, compressor 12 may be housed with motor 14 to form a hermetic unit. It is understood that the present invention may be embodied in absorption type refrigeration systems.

Compressor 12 compresses primary heat exchange medium or vaporous refrigerant flowing through line 3 from the heat exchanger 2, acting as an evaporator. The compressed gaseous refrigerant is discharged through line 11 into heat exchanger 20, acting as a condenser. Gaseous refrigerant entering heat exchanger is liquefied through heat transfer with a secondary heat exchange medium, for example, water circulating through the heat exchanger tubes 22. Liquid refrigerant from heat exchanger 20 passes through line 24 and suitable expansion means 26, for example, a thermal expansion valve, through line 36 to the heat exchanger 2. Expansion means 26 provides the requisite pressure drop between the heat exchangers during system operation. Liquid refrigerant in heat exchanger 2 is vaporized through heat transfer with the media to be cooled or chilled, for example, water circulating in the heat exchanger coils thereof.

Heat exchanger 20 comprises a generally cylindrical shell or housing 40 with opposite end members or tube sheets 42, 43 sealingly attached thereto to define cylindrical compartment 41. Tube sheets 42, 43 support plural heat exchanger coils or tubes 22 passing through compartment 41. A pair of headers 45, 46 are sealingly attached to tube sheets 42, 43 respectively and define therewith end compartments 47, 48. Compartment 47 is separated by member 50 into inlet and discharge chambers 52, 54 respectively in communication with suitable secondary heat exchange medium.

Tube sheets 42, 43 are each provided with an equal number of spaced openings 60, 61 therethrough, each of the openings 60 in tube sheet 42 being in axial alignment with a corresponding opening 61 in the opposite tube sheet 43. The terminal ends of each heat exchanger tube 22 pass through a pair of axially aligned openings 60, 61. Each terminal end of the heat exchanger tubes 22 may be expanded by suitable means (not shown) into tight engagement with the inner surface of the tube sheet 42 or 43 defining the openings 60, 61 respectively to tightly seal compartment 41 from the opposite end compartments 47, 48. Heat exchanger tubes 22 may be grouped at 21, 23 into what are commonly known as tube bundles. Tube bundles 21, 23 communicate inlet and discharge chambers 52, 54 of compartment 47 with the opposite end compartment 48. Refrigerant lines 11 and 24 communicate the heat exchanger compartment 41 with the system compressor 12 and expansion means 26 respectively.

During operation of the refrigeration system, cooling medium from conduit 56 flows through inlet chamber 52 and heat exchanger tube bundle 21 into compartment 48, and from compartment 48 through heat exchanger tube bundle 23 and outlet chamber 54 into discharge conduit 57. Gaseous refrigerant from the compressor 12 passes through line 11 into compartment 41 of the heat exchanger 20. Liquid refrigerant in compartment 41 flows through line 24 and expansion means 26 to heat exchanger 2.

Referring to FIGURES l and 2 of the drawings, one or more tube support sheets or baflles 70 are shown. Sheets 70 may be formed with paired diametrically opposite arcuate peripheral sides 71 and planar peripheral sides 72 respectively. Arcuate sides 71, having a radius substantially equal to the radius of cylindrical heat exchanger shell 40, abut the inner surface of shell 40.

In constructions where it is intended that tube support sheets 70 additionally function as bafi les to route the flow of refrigerant through heat exchanger compartment 41, tube support sheets 70 may be formed with an arcuate peripheral side terminating in a single planar peripheral side. The arcuate side, at a radius substantially equal to the radius of cylindrical heat exchanger shell 40, abuts the inner surface of the shell 40.

A plurality of openings 74 having an inner dimension slightly greater than the outer dimension of the heat exchanger tubes 22, is provided in each tube support sheet 70. Each of the openings 74 is disposed in axial alignment with a corresponding pair of openings 60, 61 in tube sheets 42, 43 respectively. Tube support sheet or sheets 70 are located within cylindrical heat exchanger compartment 41 in predetermined spaced relationship to tube sheets 42, 43. Preferably, tube support sheet or sheets 70 are fixedly secured to the inner surface of shell 40 by suitable means (not shown). The coaxial relationship between each of the plural tube receiving openings in the support sheet 70 and a pair of tube receiving openings in support sheets 42, 43 establishes a substantially straightline path for each heat exchanger tube.

Use of supporting structure of the type described heretofore having openings therein for receiving heat exchanger tubes presents two diametrically opposite problems. In order to assemble the heat exchanger, and to permit removal of one or more heat exchanger tubes for repair or replacement, the tube openings in the support sheet or sheets must have a dimension greater than the outer dimension of the heat exchanger tubes. By this means relative movement between the tubes and the support sheets, necessary during assembly of the heat exchanger, may be effected. Efficient tube support, however, decrees that the support sheet closely surround, and preferably tightly grip, the heat exchanger tube. It is appreciated therefore that if the dimension of the support sheet opening too closely approximates the outer dimension of the heat ex changer tube, tube support may be realized at the expense of very difiicult, or impossible, movement of the heat exchanger tubes through the support sheet openings. If the dimension of the support sheet openings be sufficiently great thereby permitting ready insertion, and withdrawal, of the heat exchanger tubes, excessive tube vibration and sag between adjacent supports may occur.

Applicants novel arrangement, hereinafter described, permits the use of tube support sheets with tube receiving openings therein large enough to permit ready movement of the heat exchanger tubes therethrough during assembly or disassembly of the heat exchanger while providing tight engagement between the support sheet and the heat exchanger tube passing therethrough.

In FIGURE 3 of the drawings, an enlarged view of applicants novel heat exchanger tube support structure is shown. Tube support sheet or baffle 70, having a plurality of tube receiving openings 74 therein, is preferably formed from a thermosetting resin. Re-enforcing means 80 of any suitable organic or inorganic material may be formed integrally therewith to enhance the rigidity thereof. Suitable re-enforcing material may comprise metallic wire or thread, glass fiber thread or chopped and randomly oriented glass fiber particles. Tube receiving openings 74 have a diameter slightly greater than the outer diameter of the heat exchanger tubes 22 to facilitate movement of the tubes therethrough during assembly and disassem-bly of the heat exchanger. Preferably, tube support sheets 70 are bevelled at 82 to minimize chipping of the tube support sheet during movement of tubes 22 through openings 74.

A portion of each of the openings 74 in tube support sheet 70 is defined by an expansible part 83. Preferably, the expansible part 83 comprises the inner peripheral surface of a ring-like member 86. As will be more particularly described hereinafter, member 86 is formed from an incompressible material adapted to swell or expand upon exposure to the system refrigerant. Ring-like member 86 may be integrally formed with and imbedded in the support sheet 70 coaxial with tube receiving openings '74. Ring-like members 86 preferably have an inner dimension, prior to expansion thereof, substantially equal to the dimension of the tube receiving openings 74. By closely surrounding the expansible part 83 with tube support sheet 70, subsequent swell or expansion of part 83 I upon exposure to the system refrigerant is confined to a radially inwardly direction. Since the part 83 tends to expand uniformly upon exposure to refrigerant atmosphere, the closely surrounding tube support sheet structure channels the entire expansion of part 83 radially inwardly.

While expansible part 83 is shown as being ring-like in shape, other arrangements and configurations may readily come to mind. For example, expansible part 83 may comprise one or more elements imbedded in that portion of the tube support sheet defining the tube receiving opening, the element or elements being adapted on exposure to refrigerant atmosphere to expand into contact with the heat exchanger tube in the opening.

Expansible part 83 is comprised of an elastomeric material adapted to expand or swell on exposure to a particular refrigerant. A composition adapted to expand in the presence of monofluorotrichloromethane (CCl F), commonly known as refrigerant Rl l, is shown in the following example (in parts by weight):

2-chloro-1,3-'butadiene 100 6 Zinc oxide 2-mercaptoimidazoline 0.5

An example of a composition adapted to swell when exposed to a lithium bromide (LiBr) solution, useful in absorption refrigeration systems, is as follows (in parts by Weight):

2-chloro-1,3-butadiene 100.00 Zinc oxide 5.00 Magnesium oxide 4.00 Sodium silico aluminate 40.00 Benzothiazyl disulfide (MBTS) .50 Z-mercaptoimidazoline .50 Petroleum oil 10.00 Stearic acid 3.00

In assembly of heat exchanger 20, tube support sheets or baffles 70 may be fixedly positioned in compartment 41 by siutable means (not shown) with tube openings 74 therein in axial alignment with respective pairs of tube sheet openings 60, 61. Tube sheet openings 60, 61 and tube support sheet openings 74 have a dimension slightly greater than the outer dimension of the heat exchanger tubes 22 whereby positioning of the heat exchanger tubes 22 in openings 60, 61 and 74 is facilitated.

Each of the heat exchanger tubes 22 is passed through a tube sheet opening 60 or 61, through each of the tube support sheet openings 74 axially aligned therewith into the opposite tube sheet opening 60 or 61. The end portions of each of the heat exchanger tubes 22 may be thereafter expanded by suitable means (not shown) into tight engagement with that part of tube sheets 42, 43 defining openings 60, 61 respectively. On exposure to the system refrigerant, for example, when the system is charged with refrigerant, expansible parts 83 of tube support sheets 70 expand or swell to tightly grip that portion of the outer periphery of the heat exchanger tube 22 opposite thereto. As noted heretofore, the closely surrounding tube support sheet structure funnels expansion of part 83 radially inward. By this arrangement, the heat exchanger tubes are securely held against movement relative to the tube support sheet.

Subsequent purging of refrigerant from the system causes parts 83 to contract thereby freeing the heat exchanger tubes for movement relative to the tube support sheets. Disengagement of heat exchanger tube end portions from tube sheets 42, 43 permits withdrawal of the tube from the heat exchanger.

While applicants novel tube support structure is described in connection with the system heat exchanger 20, it is appreciated that heat exchanger 2 may be similarly constructed. Additionally, tube support sheet may be formed from materials other than a thermosetting resin. For example, tube support sheets 70 may be metal.

Support sheet 70, where comprised of a thermosetting resin material, may be formed as a monolithic casting. Referring to FIGURE 4 of the drawings, a mold having a plurality of spaced cylindrical cores 91 is therein shown. Each of cores 91 may be flared outwardly at 93. An impervious covering 95, formed from a suitable material such as a silicon-rubber composition, to inhibit the adherence of the formed tube support sheet to the mold 90, preferably covers mold 90. Covering 95 includes plural spaced cylindrical portions 97 for receiving each of the mold cores 91 therein. Core covering portions 97 may be flared outwardly at 98. It is understood that the size, orientation, and number of mold cores correspond to the size, orientation, and number of heat exchanger tube openings desired in support sheet 70.

To position ring-like expansible members 86 on mold 90, an insert loading mechanism designated generally by the numeral 100 may be provided. Suitable drive means (not shown) is provided to effect predetermined relative axial movement between loading mechanism 100 and mold 90. Loading mechanism 100 includes a plurality of cylindrical loading pins 102, the number and orientation of which correspond to the number and orientation of the mold cores 91. The outside dimension of each of the loading pins 102 is preferably slightly greater than the inside dimension of ring-like member 36 to maintain member 86 on loading pin 102 prior to removal therefrom by ejector 104. If desired, members 86 may be provided with a slightly raised portion (not shown) to aid in maintaining members 86 positioned on loading pins 102 prior to removal thereof by the stripper or ejector means 104. Ejector 104 is suitably mounted for predetermined movement relative to loading pins 102.

Each of the loading pins 102 is provided with an extension 110 adapted to upset the mold covering cores 91 during the loading operation. Each of the mold cores 91 is provided with a recess 112 to accommodate loading pin extension 110. A port 116 adapted to communicate recess 112 with the ambient is provided. Alternatively, port 116 may communicate recess 112 with a source of vacuum to upset the mold core covering portions 97 in place of or in conjunction with extension 110.

In operation ring-like expansible members 86 are positioned on each of the loading pins 102. Relative closing movement between the loading mechanism 100 and the mold 90 is then initiated to cause extension 110 to upset core covering portion 97 of mold covering 95 whereby the outwardly flared portions 98 thereof collapse inwardly to permit movement of members 86 thereover. Ejector 104 may be then actuated to strip members 06 from loading pins 102 onto the mold core 91. Relative opening movement between the loading mechanism and the mold 90 is thereafter effected.

The mold 90 having ring-like expansible members 86 suitably positioned thereon may be filled substantially to the top of covering portions 07, as shown by the dotted lines in FIGURE 4, with a suitable thermosetting resin preferably in liquid form. The resin upon curing, polymerizes to form a rigid unitary structure. Openings 118 may be provided in the outer circumference of member 86 to obviate possible entrapment of air between the neck of member 86 and the mold. At the completion of the curing cycle, the formed tube sheet having a plurality of tube receiving openings therein, each of which includes expansible member 86, may be separated from the mold.

If desired, mold 90 having ring-like expansible members 86 suitably positioned thereon may be enclosed by suitable means (not shown) and a suitable thermosetting resin injected into the cavity defined by the mold, the enclosing means, and members 86. In this arrangement the thermosetting resin may be in the form of a froth which thereafter polymerizes to a rigid cellular structure. Alternately, the thermosetting resin may comprise a suit able liquid compound which upon injection into the enclosed mold cavity, foams and polymerizes into a rigid cellular structure.

In the embodiment shown in FIGURE of the drawings, each tube support sheet 70 is comprised of plural segment-s 200 suitably fastened one to another. Each segment 200 has a plurality of spaced heat exchanger tube receiving openings 202 therethrough. It is appreciated that the size, orientation and number of openings 202 are dependent upon the size, orientation and number of heat exchanger tubes to be supported. Support sheet segments 200 are formed from any suitable rigid material, prefer ably a thermosetting resin material. Tube support sheet segments 200 may be formed from metal. Where segment 200 comprises the entire tube support sheet, the segment is preferably formed with an arcuate peripheral surface portion having a radius substantially equal to the radius of the heat exchanger cylindrical shell. This general configuration and arrangement may be seen in FIGURE 2 of the drawings.

Where plural segments 200 comprise tube support sheet 70, each segment 200 is preferably formed in a generally rectangular or square shape. Abutting edges 250 of each segment may be irregular to accommodate the plurality of closely spaced tube receiving openings 202 therein.

Edges 250 of each tube support segment 200 are fastened together by a suitable means to form a unitary structure. If desired, a suitable bracing means, for example, channel-shaped member 252 may be fastened to the upper and/ or lower edges of the assembled tube support sheet to insure rigidity thereof. A pair of filler pieces 254 may be suitably fixed to the opposite ends of the assembled tube support sheet 70. Filler pieces 254 are formed with an arcuate surface 256 having a radius substantially equal to the radius of heat exchanger shell 40. Suitable fastening means (not shown) may be provided to fixedly attach the tube support sheet to the heat exchanger shell 40.

Referring to FIGURE 6 of the drawings, each tube support sheet segment 200 may be formed by fastening paired support sheet parts 204, 205 together. The mating surfaces 208, 209 of each tube support part 204, 205 respectively are provided with circular recesses 210, 211 respectively coaxial with each heat exchanger opening 202 therein. Each pair of circular recesses 210, 211 cooperate upon the joining of the support sheet parts 204, 205 together to enclose a ring-like expansible member 212.

Expansible members 212 are each formed with inner surface portions 214 and inwardly extending lip portion 215. Surface portions 214 are provided with an inner dimension before expansion of member 212 substantially equal to the outer dimension of the tube receiving opening 202 of segment parts 204, 205. The outer edges of members 212 may be bevelled at 217 for reception in undercut 206, 207 of recesses 210, 211 respectively. Members 212 are formed from a suitable material adapted to expand upon exposure to the system refrigerant.

Suitable assembly apparatus comprising relatively movable upper and lower platens 222, 223 respectively may be provided to facilitate the assembly of support sheet segments 200. Each of the upper and lower platens 222, 223 respectively include a plurality of cylindrical cores 224, 225 respectively in axial alignment with one another and substantially equal in size, orientation and number to the tube receiving openings 202 in support sheet parts 204, 205. Core 225 terminates in a portion 227 having a diameter slightly less than the outer diameter of tube receiving opening 202.

In operation support sheet part 205 may be positioned on lower platen 223 with cores 225 passing through each of the openings 202 in part 205. Expansible members 212 may be then positioned in each of the recesses 211 in surface 209 of part 205 with bevelled edge 217 thereof in groove 207. Reduced diameter portion 227 of core 225 accommodates insert lip 215. Tube support sheet part 204 is disposed on upper platen 222 with cores 224 thereof passing through openings 202 therein. A suitable adhesive bonding agent may be applied to one of the mating surfaces 208, 209 of tube support parts 204, 205 respectively.

Predetermined closing movement between upper and lower platens 222, 223 brings mating surfaces 208, 209 into contact, recesses 210 in part 204 receiving the upper part of members 212 with the upper bevelled edge 217 of members 212 in grooves 206 of part 204. Separation of upper and lower platens 222, 223 may be effected at the completion of a predetermined bonding cycle to give a unitary support sheet segment 200 having expansible members 212 fixedly positioned therein.

Alternately, asuitable elastomeric compound preferably in liquid form may be injected into the cavity defined by abutting tube support sheet parts 204, 205 and cores 224, 225 in place of the preformed expansible members 212. In this arrangement tube support sheet parts 204, 205, suitably positioned on upper and lower platen cores 224, 225 respectively and having a suitable adhesive bonding agent applied to one or the other of adjacent surfaces 208, 209 thereof, are brought into contact through predetermined movement of platens 223, 224 in a closing direction in the manner described heretofore. The upper platen core 224 may be provided with a sprue opening 230 adapted to communicate with a source of elastomeric compound. Runner 232 is provided in core 224 to communicate sprue opening 230 with the cavity formed by recesses 210, 211 and core-s 224, 225. With tube support sheet parts 268, 209 in contact with one another, elastomeric compound is passed through the communicating sprue and runner openings 230, 232 into the cavity formed by the contacting tube support sheet parts and the platen cores. At the completion of a predetermined curing cycle, upper and lower platens 222, 223 may be separated and the tube support sheet segment 200 having a plurality of expansible portions 212 formed therein withdrawn.

Applicants unique arrangement for supporting heat exchanger tubes realizes the advantages of what were heretofore opposing considerations in tube type heat exchanger constructions, that is, the requirement that tube receiving openings be dimensioned larger than the outer dimension of the heat exchanger tubes to facilitate assembly of the heat exchanger and the requirement that the support apparatus tightly grip the heat exchanger tubes for efficient support.

While I have shown preferred embodiments of the present invention, it will be obvious that other modifications may be made without departing from the scope of the invention as limited only by the appended claims.

I claim:

1. In a heat exchange apparatus having first and second compartments adapted to communicate with first and second heat exchange mediums respectively, with at least one heat exchanger tube passing through the first compartment in communication with the second compartment, the combination of: at least one sheet-like tube support member in said first compartment having an opening therethrough through which said heat exchanger tube is adapted to pass, said opening having a dimension greater than the outer dimension of said heat exchanger tube; and tube fastening means imbedded in said member and forming a wall portion of said opening adapted to abut at least a portion of the outer periphery of said heat exchanger tube in said opening, said tube fastening means comprising the sole means for fastening said tube to said support member, said tube fastening means being comprised of an elastomeric material which expands upon exposure to said first medium, said material being substantially unaffected by temperature conditions of said first medium.

2. Heat exchange apparatus according to claim 1 in which said tube support member is comprised of a thermosetting resin material.

3. Heat exchange apparatus according to claim 1 in which said tube fastening means comprises plural elements disposed about the circumference of said tube receiving opening.

4. Heat exchange apparatus comprising: a housing defining a compartment adapted to communicate with first heat exchange medium; plural heat exchanger tubes extending through said compartment adapted to communicate with second heat exchange medium; and means for maintaining said heat exchanger tubes in predetermined spaced relationship including a tube support sheet in said housing having openings therethrough spaced in said predetermined relationship for receiving heat exchanger tubes therethrough, said openings having a dimension greater than the outer dimension of said heat exchanger tubes; and expansible means comprising the sole means for securing said heat exchanger tubes to said support sheet, said expansible means comprising an elastomeric material which expands upon exposure to said first medium, said material being substantially unaffected by temperature conditions of said first medium.

5. Heat exchange apparatus according to claim 4 in which said expansible means is positioned between said heat exchanger tubes and the tube support sheet.

6. Heat exchange apparatus according to claim 4 in which said expansible means comprises an element having an opening therein with a dimension before expansion of said element substantially equal to the dimension of said tube receiving opening.

7. Heat exchange apparatus according to claim 4 in which said tube support sheet comprises a thermosetting resln.

8. In a heat exchanger, the combination of plurality of heat exchanger tubes; a plate-like tube support member; said member being formed from a thermosetting resin and having plural spaced tube receiving openings therethrough having a dimension greater than the outer dimension of said heat exchanger tubes to facilitate movement of said heat exchanger tubes through said openings; and an expansible tube fastening element in said member adjacent each of said tube receiving openings having an exposed surface defining a portion of said tube receiving opening; said expansible elements comprising the sole means for fastening said tubes to said member, said expansible elements being comprised of an elastomeric material adapted to swell when exposed to heat exchange medium whereby the exposed surface of said expansible elements tightly engages the heat exchanger tubes in said member openings, swelling of said material being substantially unaffected by temperature conditions of said medium.

9. A heat exchanger according to claim 8 in which said expansible tube fastening elements comprise a ringlike device with an inner dimension before exposure to heat exchange medium substantially equal to the dimension of said member tube receiving opening.

10. In a structure for supporting heat exchanger tubes in predetermined spaced relationship one to another, the combination of: first and second members having plural axially aligned openings therein, each pair of openings being adapted to receive a heat exchanger tube therethrough; and expansible means comprising an elastomeric material between said first and second members at each of the tube openings operable upon exposure to heat exchange medium to expand into contact with the heat exchanger tube in said pair of openings said expansible means being substantially unaffected by temperature conditions of said heat exchange medium, adjacent surfaces of said first and second members having recess means formed therein communicating with each of said first and second member tube receiving openings for receiving said expansible means.

11. Tube support structure as recited in claim 10, said recess means being substantially cylindrical and coaxial with its respective tube receiving opening.

References Cited UNITED STATES PATENTS 2,310,927 2/1943 Bay 285-213 X 2,550,560 4/1951 Heron 285328.4 X 2,859,948 11/1958 Callard -178 X 2,964,437 12/1960 Appleton et a1. 156293 3,032,462 5/1962 Saporito 156-242 3,088,555 5/1963 Karlgaard 188-88 3,186,924 6/1965 Williamson 202-173 3,187,810 6/1965 Helin et a1 165-158 3,191,674 6/1965 Richardson 165-158 ROBERT A. OLEARY, Primary Examiner. FREDERICK L. MATTESON, JR., Examiner. MEYER PERLIN, A. W. DAVIS, Assistant Examiners. 

10. IN A STRUCTURE FOR SUPPORTING HEAT EXCHANGER TUBES IN PREDETERMINED SPACED RELATIONSHIP ONE TO ANOTHER, THE COMBINATION OF: FIRST AND SECOND MEMBERS HAVING PLURAL AXIALLY ALIGNED OPENING THEREIN, EACH PAIR OF OPENINGS BEING ADAPTED TO RECEIVE A HEAT EXCHANGER TUBE THERETHROUGH; AND EXPANSIBLE MEANS COMPRISING AN ELASTOMERIC MATERIAL BETWEEN SAID FIRST AND SECOND MEMBERS AT EACH OF THE TUBE OPENINGS OPERABLE UPON EXPOSURE TO HEAT EXCHANGE MEDIUM TO EXPAND INTO CONTACT WITH THE HEAT EXCHANGER TUBE IN SAID PAIR OF OPENINGS SAID EXPANSIBLE MEANS BEING SUBSTANTIALLY UNAFFECTED BY TEMPERATURE CONDITIONS OF SAID HEAT EXCHANGE MEDIUM, ADJACENT SURFACES OF SAID FIRST AND SECOND MEMBERS HAVING RECESS MEANS FORMED THEREIN COMMUNICATING WITH EACH OF SAID FIRST AND SECOND MEMBER TUBE RECEIVING OPENINGS FOR RECEIVING SAID EXPANSIBLE MEANS. 